Method of treating hydrocarbon base



with a base, and also to United States Patent Ofifice METHOD or TREATING HYDROCARBON BASE LUBRICANTS WITH A PHOSPHORUS SULFIDE IN THE PRESENCE OF BUTYL RUBBER AND PRODUCT Everett C. Hughes, Shaker Heights, Harvey E. Alford, Amherst, and John D. Bartleson, Beachwood Village, Ohio, assignors to The Standard Oil Company, Cleveland, Ohio, a corporation of Ohio No Drawing. Application August 20, 1952, Serial No. 305,512

12 Claims.. (Cl. 25232.7)

This invention relates to a process carbon base lubricants proved process of treating hydrocarbon lubricants with a 5 small amount of butyl rubber, followed th in which the lubricant is in close contact They are also suitable for use in extreme pressure lubricants, e. g., mods and greases containing acteristics of the oil. formed during the reaction and can be removed byfiltration to produce a desirable product.

However, from time to time the sludge which forms in base lubricating oilstocks are sulfide in the presence may form in As a result, sludge the desired reaction product butyl rubber in consequence makes application of the process on a large readily can by filtration.

ossible commercial cale.

The other desirable properties of the sulfide refined oil enot affected. In fact, the reaction product may have higher sulfur content and, when reacted with a base, in ddition higher ash. .Inasmuch as the beneficial engine surfaces, metal compounds and hightem- Only minor amounts of sludge are desirable.

not follow and is desirable, but not essential.

'stocks can be used.

2,695,271 Patented Nov. 23, 1954 performance characteristics of the ciated with a high sulfur ciated that such an improvement would vantageous. Further, the viscosity index oil is improved.

ome oils are quite unreactive, and do not respond readily to treatment with a phosphorus sulfide. White oil is an example. Many such oils react readily with phosphorus presence of butyl rubber.

treated oil are assoand ash content,

be notably adof the finished as petroleum and 011s produced by dehydrogenation and the like and these are separated out. Clay treatment may or may Where necessary, a separate propane or thelike deasphalting treatment may be used in connection with the solvent refining.

The process of the invention also is applicable to hydrocarbon base lubricant stocks obtained by other refining methods, such as acid-treated lubricant stocks, and to white oils.

The reaction phosphorus sulfide 1n the from one to two hours is an adequate reaction time. The reaction time is a function of temperature, the amount of sulfide employed, the

degree of subdivision of the reactants, the efiiciency of mixing and the concentration thereof in the diluent, if present.

Any phosphorus sulfide reactive will im- To obtain a marked improvebutyl rubber should be present. obtained when amounts within to about 1% are used. When Any amount of butyl rubber below about 2% prove the final product. ment, at least about 0.25% and optimum results are the range of about 0.5%

butyl rubber inhibit the desired reaction with the phosphorus sulfide.

' It is desirable to dissolve the butyl rubber in the oil before starting the reaction.

the oil at an elevated to the resulting solution. a

The reaction of the hydrocarbon base stock with the it will be appre- -be carried out in the presence or of butyl rubber can absence of air, or in an atmosphere of inert or nondeleterious gas, such as nitrogen. If an inert gas such as nitrogen is bubbled through the reaction mixture, the reaction product is stabilized against liberation of hydrogen sulfide. The reaction also may be carried out under pressure, as. for example, the pressure generated through liberation of gases in the course of the reaction when the reaction is carried out in a closed vessel.

The reaction temperature varies with the hydrocarbon stock. Temperatures of at least 275 F. are desirable, while temperatures in the range of from about 300 to about 450 F. are preferred in many cases. The temperature should be below the temperature at which the reaction product or the reactants would be decomposed.

The final refined oil then can be centrifuged or filtered to remove by-products, sludge and unreacted material. If a volatile diluent is used, it can be: removed by evaporation or distillation, preferably under low pressure and at low temperatures. The treated product can be used as a lubricant or in a blend together with other lubricants, lubricating oil base stocks, or lubricating agents, e. g., with soap or the like in a grease.

If desired, the reaction product can be further improved particularly with respect to detergency by reaction with a base to form a metal compound or derivative. The metal derivatives may be formed from one or more metal compounds, such as the sulfides, oxides, hydroxides, carphosphorus sulfide in the presence hides and cyanarnides or metals selected from groups I, ll

and'III of the periodic table, such as potassium, zinc, barium, calcium, magnesium, sodium, strontium and aluminum. The alkali and alkaline earth metal derivatives are preferred. For particular uses, the heavier metals, i. e., those below zinc in the electromotive series, such as chromium, cadmium, tin, lead, antimony, bismuth, arsenic and the like, have been used. In the treatment with the metal compound or base, the reaction can be effected at temperatures in the range of about 100 to about 400 F., a temperature in the range of about 180 to 350 F. being preferred, if the sulfide refined stock has been subjected to a temperature of at least 300 F. Alternatively, the metal derivative may be prepared at or subjected to a temperature of 300 F.

From about 0.25 to about equivalents of the metal compound may be used per mol of the sulfide used in preparing the sulfide refined stock. Preferably about 6 to about 12 equivalents are used.

The following specific examples are illustrative of the principles and advantages of the invention:

Example 1 Light white oil (600 grams) and 3 grams of butyl rubber were heated for three hours at 300 F. under a nitrogen atmosphere until the butyl rubber had completely dissolved. PzSs (1.2 grams, 0.2%) was added and the reaciton mixture heated for one hour at 300 F. under a nitrogen atmosphere. Substantially no sludge formed during the reaction and that which did form was hard, non tacky, and did not adhere to the sides of the flask; The product was filtered easily, a 98.5% yield being obtained, and analyzed as follows: per cent S 0.09, O. D. 238, acid No. 3.01, per cent ash 0.06, viscosity index 106.8.

The product was stable to formation of hydrogen sulfide for one week at room temperature in the absence of water.

, When this oil was treated with P255 alone at 300 F. for one hour, very little reaction occurred, and most of the P285 was recovered. The product had a sulfur content of 0.025%.

Four hundred grams of the above Pass-butyl rubberoil-reaction product was reacted with 1.6 grams of flake KOI-l at 250 F. for two ,hours under a nitrogen atmosphere. Filter aid (2%) was added and the mixture filtered. The KOH appeared to have reacted completely and a 97.7% yield was, obtained. This product analyzed as follows: per cent S 0.07, O. D. 47.6, alkaline No. 0.22, per cent ash 0.23, viscosity index 110.

The metal derivative was subjected to the Polyveriform test: corrosion: 7.7 mg, viscosity increase: -12 SSU at 100 F., pentane insolubles: 2.68%, neutralization N0. 3.08, lacquer rating: A, sludge rating: A.

.. grams of 4 Example 2 No. 300 solvent extracted neutral oil (viscosity 300 SSU at F., 600 grams) was reacted with 2.7 grams phosphorus pentasulfide at 300 F. for one hour under a nitrogen atmosphere. Very little sludge was formed, and this was hard, nontacky and readily filtered out. A yield of 97.8% was obtained after filtration.

This material (87 grams) was blended with 4.9 grams each of 78 solvent extracted bright stock (78 SSU at 210 F.) and 250 solvent extracted bright stock (250 SSU at 210 F.) to give a final lubricating oil meeting the specifications for an S. A. E. No. 20 motor oil. This material analyzed as follows: per cent S 0.39, per cent P 0.065, O. D. 90.6, acid No. 1.99, per cent ash 0.015.

To another portion (500 grams) of the above reaction product (before blending with bright stock) was added 4.5 grams of potassium hydroxide and the mixture was heated at 250 F. for two hours under a nitrogen atmosphere. The product was filtered following addition of 2% filter aid. The potassium hydroxide appeared to have reacted completely and a 97.6% yield was obtained. 27.6 grams each of 78 and 250 solvent extracted bright stock (78 and 250 SSU at 210 F. respectively) were added to give the final oil blend. The product analyzed as follows: per cent S 0.33, per cent P 0.76, O. D. 46.8, alkaline No. 0.60, per cent ash 0.35.

Example 3 No. 300 solvent extracted neutral oil (300 SSU at 100 F.), 885 grams, and 5 grams of butyl rubber were heated at 300 F. under a nitrogen atmosphere until all of the butyl rubber had dissolved. This required four hours. The solution then was mixed with 3.94 grams phosphorus pentasulfide for one hour at 300 F. in a nitrogen atmosphere. A very small amount of sludge formed which remained in suspension and was easily removed by filtration at the conclusion of the reaction. 98.5% yield was obtained.

To 280 grams of this product were added 15.9 grams each of 78 and 250 solvent extracted bright stock to give a final lubricating oil blend which met the specifications for an S. A. E. No. 20 motor oil. The product analyzed as follows: per cent S 0.45, O. D. 231, acid No. 1.85, per cent ash 0.04, viscosity index 103.8.

Example 3A the reaction product (before blending) of Example 3 were added 5.34 grams of potassium hydroxide and the mixture reacted at 250 F. for two hours un' der a nitrogen atmosphere. Two per cent of filter aid was added and the product filtered. A 99.3% yield was obtained.

To this material were added 33.7 grams each of 78 and 250 solvent extracted bright stock to give a lilbl'l cating oil which met the specifications for an S. E. No. 20 motor oil. The product analyzed as follows: per cent S 0.37, O. D. 133.2, alkaline No. 1.05, per cent ash 0.48, viscosity index 105.2.

For comparison, oils were made without the butyl rubber as follows:

S. A. E. No. 20

To 600 grams of blended solvent extracted neutral oil (1,000 grams) was reacted with four grams of phosphorus pentasulfide for one hour at 300 F. under a nitrogen atmosphere. Some sludge was formed in the reaction which was removed with difficulty, due to its tacky character. The product analyzed as follows: per cent S 0.41, per cent P 0.10, O. D. 108.7, acid No. 1.97, per cent ash 0.

To 700 grams of this reaction product was added 5.6 flake KOH and the mixture reacted at 250 F. a nitrogen atmosphere. Two per cent filter aid was added and the product was filtered. A 97.4% yield was obtained. This product hadthe following analysis: per cent 5 0.46, per cent P 0.11, O. D. 73.5, alkaline No. 0.75, per cent ash 0.

Thus the products reacted in th rubber are fully comparable, and in alkaline ash slightly better than the products reacted in sence of butyl rubber.

To show the effect of butyl rubber the same amount of butyl rubber was added to the initia reaction product and to the second reaction product ob tained after reaction Withdhe first product of potassiu hydroxide. The viscosity index of the former was 106. and of the latter 106.7. A comparison of these resul for two hours under presence of butyl number and the ab- .ash 0.31, viscosity index 99.6.

with the viscosity index he motor oils obtained were subjected to the Polyveriform test for 10 hours at 325 F. (Analytical Chemistry 21 737 (1949).

Oil-Pb Viscosity Neut. Iusols Example Corrosion Increase N o. Mglm 1 g 5 Untreated S. A. E. No. 20

I OH 19.3 170 3 92 57.7 3. 5 -30 0 95 4. 8 Control No bu. rubber 4. 3 4. 5 0 62 6. 4 3A 39 0 78 15.6

COREY N63511: Eh'BBEII 10. 0 I84 9. A

show that the butyl 30 was added 2.67

The Polyveriform test results rubber does no materially interfere Example 4 S. A. E. No. 20 motor oil (435 SSU at 100 grams, formed by a blend of 88.5 extracted neutral oil (300 SSU at 100 F.), 5 parts of 250 bright stock (250 SSU at 210 F.) and 5 parts of 78 bright stock (78 SSU at 210 F.), and 20 grams of Paratone (a polyisobutylene), and 4 grams of phosphorus pentasulfide were reacted at 300 F. for one hour under a nitrogen atmosphere. filtered but a fair proportion of sticky A 96% yield was obtained of a product which analyzed as follows: per cent S 0.31, O. D. 1 No. 1.57, per cent ash 0.001, viscosity index 97.2.

per cent S 0.30, O. D. 84.2, alkaline No. 0.65, per cent (Example 4A in the table.)

Each of these products was subjected to the Polyveriform test with the following results:

Cu-Pb Viscosity Neut. Insols, Example Corrosion Increase N o. g

10 g. R Untreated S. A. E. No.

l Motor Oil These results show 0t improve the good, as a (1 4A, respectively, shows.

Example 5 o. 300 solvent extracted neutral oil (300 SSU at F., 885 grams) and 5 grams of butyl rubber were very small amount of hard, which readily was removed by filtration. A 98.5% yield was obtained.

To 280 grams of the product was added 15.9 grams each of 78 and 250 solvent extracted bright stock to give a motor oil meeting the specifications for an S. A. E. No. 20 motor oil. This product analyzed per cent S 0.26, O. D. 174.8, acid No. 1.3, per cent ash 0.007, viscosity index 105.

To 600 grams of the above product (before blending) Example 6 Light white oil (600 grams) and 6 grams of butyl rubber were heated for three hours at 300 F. under a bber was completely dissolved. To th1s solution was added 2.4 grams P2S5 F. for one hour with A small amount of hard, non-tacky separated by filtration. 0.18, per cent P 0.08, 2.0, per cent ash 0.02.

Example 6.4

pletely and the reaction product analyzed per cent 8 0.09, per cent P 0.05, O. D. 108, alkaline No. 097, per cent ash 0.43, viscosity index 113.55.

Pentane- M mSJ Lacquer Sludge products were subjected to the Polyresults of which are reported below:

These reaction veriform test, the

. may be includ Example Light whiteoil (1400 grams) and 28- gramsofbutyl rubber wereheatedfon three hoursat: 300 F. with nitrogen stripping until the rubber was completely dissolved. To: 1200' grams of thisv solution was added. 4.8 grams (04%) P255 and the mixture reacted at 300 F. for one hour with nitrogen stripping. A small amount of crystalline sludge formed which was readily separated by filtration. 0.03, percent P 0.03, O. D. 7.3, acid No. 1.14, percent ash 0.02, viscosity. index 131.4. This shows that no appreciable reaction occurred.

To. 600 grams of. thisreaction product was added 4.8 grams of flake potassium hydroxide and the mixture heated at 250 F. for two hours with nitrogen stripping. The mixture was filtered with the aid of 2% filter aid. The potassium hydroxide appeared not to have reacted, and was recovered upon filtration. The reaction product analyzed percent S zero, percent P :03, 0. D. 15.6, acid No. 0.44, percent ash 0.09, viscosity index 133.3, showing that substantially no reaction occurred.

Butyl rubber, as the term is used in the claims, refers to GR-l, the product of the copolymerization of isobutene with a small amount of isoprene or butadiene, and this is known to have the chain structure:

and contains butadiene random intervals 1H 'th6 by the inactivity ot Paratone. butene polymer which is fully saturated, and it would be expected if the above theory were correct that it would be unable to take part inthe reaction because of the absence of carbon-to-carbon double bonds. This in fact has been shown to be the case. N, an acrylonitrile polymer, are wise, appear to be ineffective in the processes of the invention. Completely vulcanized butyl rubber, likewise, is oilv insoluble and. is not employed. Unyulcaniz ed or partially vulcanized butyl rubbers are employed in the recess of theinvention.

If desired, the may be used in or lubricant agents, e. g.,

insoluble improved lubricants of the invention blends. together with other lubricants with soap or the like in a grease. If desired, an agent for improving the clarity of the Oil ed, e. g., lecithin, lauryl alcohol and the like. If desired, an agent for preventing foaming may be included, e. g., tetra-amyl silicate, an alkyl orthocarbonate, ortho-formate or ortho-acetate or a polyalkyl silicone oil.

All parts and percentages in the specification and claims are by weight.

Buna S, a styrene-butadiene polymer, and Bun-a in oil and, like- We claim:

1. A method of' processing hydrocarbon. lubricating oil stock which method comprises treating said stock withan amount of phosphorus pentasulfide' in the range of about 0.1 to about 0.75% at a temperature, in the range of about 275 to about 450 F. in the presence of a small amount within the range from about 0.25 to 2% of butyl rubber.

2. A composition suitable for use as a lubricant and as'a lubricant additive obtained by the process-of claim 11.

3. A method of processing hydrocarbon lubricating oil stock to yield an oil having improved serviceproperties which method comprises treating said: stock with an amount of phosphorus pentasulfide in the range of'about 0.1. to about 0.75% at a temperature in the range of about 275 toabout 450 F. in the presence ofa-small' amount within the range from about 0.25 to 2% of butyl rubber andv then with an. amount of. a base in the range of about 0.25- to about 15 equivalents per mol of the phosphorus sulfide.

4. A composition suitable for use as a lubricant and as a lubricant additive obtained by the-process'of. claims:

5. The method of, claim 1 wherein the stock is treated with an amount of phosphorus pentasulfide in: the rangeof about 0.25 to about 0.6% at a temperature in-the range of about 300to 450F.

6. A composition suitable for use as a lubricant and'as a lubricant additive obtained by the process of cl 7. The method=of claim 3 wherein thestock= is treated with an amount of phosphorus pentasulficle in the: range of about 0.25; to about 0.6% ata temperature in, the rangeof about 300 to 450 and then with an amount of a metal base in the range of about 1.0- to: about 15 equivalents per mol of the phosphorus pentastllfide.

8. A composition suitable for use as a lubricant'andias a lubricant additive obtained by the process of claim 7.

9. The method of claim 7 wherein the stock is treated with an amount of-dry potassium hydroxideinthe range of about 0.6 to about 0.8% by weight of the stock. 10.- A composition suitable for use as a lubricant and as a lubricant. additive; obtainedby the; process ofrclaim 9; 11. A method of processing hydrocarbon lubricating oil stock to yield an oil having improved; service: properties which; method comprises treating sa'd stock with an amount of. phosphorus pentasulfide in the: range: of about 0.1 to about 0.75% at a temperature in the range of about 275 to about 450 F. in the presenceof a small amount within the range '[romabout 0.25 to 2% ofbutyl rubber and then, with a base in the amount of at least abfiiuit 0.25 equivalent per-mol of the phosphoruspentw su e.

12. Acompositionsuitable fornuse as a lubricant and as a lubricant additive obtained by the processoficlaim 1.1-.

References Cited' in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Concise Chemical and Technical nett, Chemical Pub. Co.. Brooklyn, pagesVII.and 159..

Dictionary]? Ben New York, 1947, 

1. A METHOD OF PROCESSING HYDROCARBON LUBRICATING OIL STOCK WHICH METHOD COMPRISES TREATING SAID STOCK WITH AN AMOUNT OF PHOSPHORUS PENTASULFIDE IN THE RANGE OF ABOUT 0.1 TO ABOUT 0.75% AT A TEMPERATURE IN THE RANGE OF ABOUT 275* TO ABOUT 450* F. IN THE PRESENCE OF A SMALL AMOUNT WITHIN THE RANGE FROM ABOUT 0.25 TO 2% OF BUTYL RUBBER. 